*Constantius I (Flavius Valerius Constantius Chlorus) "the Pale" Emperor
born in 0242
died Eboracum (York, England) 25 July 0306

father:
*Eutropius of Dardania

mother:
*Claudia Crispina
born about 0221

siblings:
unknown

spouse (1st):
*Helen (Helena of the Cross) of Britain ("Britannica")
born in 0265 Bythnia, Britain
died 0336/37

children:
*Constantine the Great (Flavius Valerius Aurelius Constantinus) Emperor
born 17 February 0265 Naissus in Moesia
died in May 0336/37
buried in the church of the Holy Apostles in Constantinople

biographical and/or anecdotal:
Governor of Dalmatia, appointed Caesar to rule Gaul and Britain March 1, 293. He was the son of *Eutropious, a Dardanian nobleman descended from the *Gordiani, and his wife, *Claudia, daughter of *Claudius II (Marcus Aurelius Flavius Claudius Gothicus), a virtuous and worthy Roman Emperor (268-270), who was a soldier, statesman, and a distinguished officer. Born in Illyria 214, he was trained in the hard school of warfare on the Danube frontier, and died of the Plague in 270, aged 55, whereupon his brother Marcus Aurelius Claudius Quintillus became Emperor. Constantius I became Emperor of Rome in May 305, and in right of his wife, King of England. He was born in 242 and died at Eboracum (present day York, England) on July 25, 306. On becoming "Caesar," he was required by Diocletian to put aside *Helena and to take Maximian's stepdaughter, Theodora, as his wife. From the first union, *Helena and *Constantius I had an illegitimate son, *Constantine the Great. He married (2) Theodora, daughter of Maximinus, Roman Emperor.
Gibbon says *Claudia was the niece of *Claudius II (Marcus Aurelius Flavius Claudius Gothicus).
Encyclopedia Brittanica maintains Constantius I's descent from Claudius Gothicus was a fiction.
Enter at your own risk.

notes or source:
HBJ & ancestry.com